Linear movement units are used in various technical fields, particularly for robots or manipulators. Such units comprise a linear guiding device including at least one guide rod or guide section as well as a moving unit guided thereby. The moving unit is ordinarily displaced along this guiding device by some drive. In order to lock the moving unit in a desired position, a locking device is provided.
EP-B-452 702 (=U.S. Pat. No. 5,184,700) discloses a locking device of the kind described above, i.e. comprising two clamping members which has each a clamping opening for the guide rod. The clamping members are pivotal into and out of their clamping position by an actuating unit. It has been found that a moving unit in motion cannot sufficiently quickly be locked by the known device to the guide rod. The clamping force achieved is apparently too small so that the moving unit splutters further in small jumps into an undefined position.